| Message ID | 20180226152253.GA19446@arm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
Hi Will, On Mon, Feb 26, 2018 at 4:22 PM, Will Deacon <will.deacon@arm.com> wrote: > On Mon, Feb 26, 2018 at 04:16:19PM +0100, Geert Uytterhoeven wrote: >> On Mon, Feb 5, 2018 at 5:42 PM, Mark Rutland <mark.rutland@arm.com> wrote: >> > To support ACPI systems, we need to request IRQs before CPUs are >> > hotplugged, and thus we need to request IRQs before we know their >> > associated PMU. >> > >> > This is problematic if a PMU IRQ is pending out of reset, as it may be >> > taken before we know the PMU, and thus the IRQ handler won't be able to >> > handle it, leaving it screaming. >> > >> > To avoid such problems, lets request all IRQs in a disabled state, and >> > explicitly enable/disable them at hotplug time, when we're sure the PMU >> > has been probed. >> > >> > Signed-off-by: Mark Rutland <mark.rutland@arm.com> >> >> This is now commit 6de3f79112cc26bf in v4.16-rc3, and causes a BUG during >> CPU offlining (e.g. during system suspend, or during boot with >> CONFIG_ARM_PSCI_CHECKER=y). >> >> With CONFIG_ARM_PSCI_CHECKER=y: >> >> psci_checker: PSCI checker started using 6 CPUs >> psci_checker: Starting hotplug tests >> psci_checker: Trying to turn off and on again all CPUs >> BUG: sleeping function called from invalid context at kernel/irq/manage.c:112 >> in_atomic(): 1, irqs_disabled(): 128, pid: 15, name: migration/1 >> no locks held by migration/1/15. >> irq event stamp: 192 >> hardirqs last enabled at (191): [<00000000803c2507>] >> _raw_spin_unlock_irq+0x2c/0x4c >> hardirqs last disabled at (192): [<000000007f57ad28>] multi_cpu_stop+0x9c/0x140 >> softirqs last enabled at (0): [<0000000004ee1b58>] >> copy_process.isra.77.part.78+0x43c/0x1504 >> softirqs last disabled at (0): [< (null)>] (null) >> CPU: 1 PID: 15 Comm: migration/1 Not tainted 4.16.0-rc3-salvator-x #1651 >> Hardware name: Renesas Salvator-X board based on r8a7796 (DT) >> Call trace: >> dump_backtrace+0x0/0x140 >> show_stack+0x14/0x1c >> dump_stack+0xb4/0xf0 >> ___might_sleep+0x1fc/0x218 >> __might_sleep+0x70/0x80 >> synchronize_irq+0x40/0xa8 >> disable_irq+0x20/0x2c > > Given that these things are CPU-affine, I reckon this should be > disable_irq_nosync. Mark? > > Will > > --->8 > > diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c > index 0c2ed11c0603..f63db346c219 100644 > --- a/drivers/perf/arm_pmu.c > +++ b/drivers/perf/arm_pmu.c > @@ -638,7 +638,7 @@ static int arm_perf_teardown_cpu(unsigned int cpu, struct hlist_node *node) > if (irq_is_percpu_devid(irq)) > disable_percpu_irq(irq); > else > - disable_irq(irq); > + disable_irq_nosync(irq); > } > > per_cpu(cpu_armpmu, cpu) = NULL; Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Thanks! Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
On Mon, Feb 26, 2018 at 03:22:53PM +0000, Will Deacon wrote: > On Mon, Feb 26, 2018 at 04:16:19PM +0100, Geert Uytterhoeven wrote: > > On Mon, Feb 5, 2018 at 5:42 PM, Mark Rutland <mark.rutland@arm.com> wrote: > > > To support ACPI systems, we need to request IRQs before CPUs are > > > hotplugged, and thus we need to request IRQs before we know their > > > associated PMU. > > > > > > This is problematic if a PMU IRQ is pending out of reset, as it may be > > > taken before we know the PMU, and thus the IRQ handler won't be able to > > > handle it, leaving it screaming. > > > > > > To avoid such problems, lets request all IRQs in a disabled state, and > > > explicitly enable/disable them at hotplug time, when we're sure the PMU > > > has been probed. > > > > > > Signed-off-by: Mark Rutland <mark.rutland@arm.com> > > > > This is now commit 6de3f79112cc26bf in v4.16-rc3, and causes a BUG during > > CPU offlining (e.g. during system suspend, or during boot with > > CONFIG_ARM_PSCI_CHECKER=y). > > > > With CONFIG_ARM_PSCI_CHECKER=y: > > > > psci_checker: PSCI checker started using 6 CPUs > > psci_checker: Starting hotplug tests > > psci_checker: Trying to turn off and on again all CPUs > > BUG: sleeping function called from invalid context at kernel/irq/manage.c:112 > > in_atomic(): 1, irqs_disabled(): 128, pid: 15, name: migration/1 > > no locks held by migration/1/15. > > irq event stamp: 192 > > hardirqs last enabled at (191): [<00000000803c2507>] > > _raw_spin_unlock_irq+0x2c/0x4c > > hardirqs last disabled at (192): [<000000007f57ad28>] multi_cpu_stop+0x9c/0x140 > > softirqs last enabled at (0): [<0000000004ee1b58>] > > copy_process.isra.77.part.78+0x43c/0x1504 > > softirqs last disabled at (0): [< (null)>] (null) > > CPU: 1 PID: 15 Comm: migration/1 Not tainted 4.16.0-rc3-salvator-x #1651 > > Hardware name: Renesas Salvator-X board based on r8a7796 (DT) > > Call trace: > > dump_backtrace+0x0/0x140 > > show_stack+0x14/0x1c > > dump_stack+0xb4/0xf0 > > ___might_sleep+0x1fc/0x218 > > __might_sleep+0x70/0x80 > > synchronize_irq+0x40/0xa8 > > disable_irq+0x20/0x2c > > Given that these things are CPU-affine, I reckon this should be > disable_irq_nosync. Mark? Given IRQs are disabled, this should be fine, yes. FWIW, if you spin this as a patch: Acked-by: Mark Rutland <mark.rutland@arm.com> Mark. > > Will > > --->8 > > diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c > index 0c2ed11c0603..f63db346c219 100644 > --- a/drivers/perf/arm_pmu.c > +++ b/drivers/perf/arm_pmu.c > @@ -638,7 +638,7 @@ static int arm_perf_teardown_cpu(unsigned int cpu, struct hlist_node *node) > if (irq_is_percpu_devid(irq)) > disable_percpu_irq(irq); > else > - disable_irq(irq); > + disable_irq_nosync(irq); > } > > per_cpu(cpu_armpmu, cpu) = NULL;
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index 0c2ed11c0603..f63db346c219 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -638,7 +638,7 @@ static int arm_perf_teardown_cpu(unsigned int cpu, struct hlist_node *node) if (irq_is_percpu_devid(irq)) disable_percpu_irq(irq); else - disable_irq(irq); + disable_irq_nosync(irq); } per_cpu(cpu_armpmu, cpu) = NULL;